Cheetahs left N America 100K years ago

Cheetahs disappeared from North America, when the last glacial retreat caused an abrupt extinction resulting in the loss of many large mammals from the region, including cheetahs and pumas

Cheetahs started migrating 1,00,000 years ago from North America towards their current habitat in the African plains, triggering the first major reduction in the species’ gene pool, a new study has found.

The modern African cheetah (Acinonyx jubatus) is found across eastern and southern Africa, but it is highly endangered because of their small free ranging population and inbreeding.

Researchers from St. Petersburg State University in Russia, in collaboration with Beijing Genomics Institute in China and Cheetah Conservation Fund in Namibia, sequenced the genome from a male Namibian cheetah, called “Chewbaaka”, and six other wild cheetahs from Tanzania and Namibia.

This gave further insight into the evolutionary history of the species and the breadth of genome impoverishment, which elevates juvenile mortality, causes extreme abnormalities in sperm development and increases vulnerability to infectious disease outbreaks.

A total of 18 cheetah genes showed damaging mutations and one gene in particular, AKAP4, showed a large number of mutations, which could harm sperm development and may explain why cheetah have a large proportion of defective sperm, and hence their low reproductive success.

The cheetah is descended from a relative of American pumas and their fossil record extends across the Americas, Europe and Asia. The species has suffered two population bottlenecks — an event whereby the population is rapidly reduced due to environmental factors, researchers said.

The first of these took place 1,00,000 years ago, around the late Pleistocene — a geological period shaped by repeated glaciations, when cheetahs started to move towards Asia across the Beringian landbridge and then travelled south to Africa.

This migration was punctuated with dwindling populations and limited gene flow due to the individuals’ own vast territory boundaries, measuring 300-800 square miles, thereby increasing incestuous mating.

The second bottleneck around 10-12,000 years ago, further reduced numbers, leading to further loss of endemic variability observed in modern cheetahs.

This is because cheetahs disappeared from North America, when the last glacial retreat caused an abrupt extinction resulting in the loss of many large mammals from the region, including cheetahs and pumas.